Find the access side, label, actuator, fusible link, sleeve, blade area, or inspection point.
Check that permanent access remains reachable after walls, ceiling, insulation, hangers, and other trades are installed.
Ask foreman
In Fire/Smoke Dampers, Access Doors & Rated Assemblies, I’m looking at: What do I do when duct insulation covers required access? What should I verify before I cut, drill, seal, cover, move, or install?
Do not
Do not treat damper or rated-assembly work like normal duct.